This Transistor's Made From a Molecule and a Few Atoms

It might look like some kind of primary school abstract painting, but you’re actually looking at a microscopic transistor which is made up of a single molecule and a smattering of atoms.

An international team, including researchers from the US Naval Research Laboratory and the NTT Basic Research Laboratories in Japan, built this tiny little device using a scanning tunnelling microscope. They used that to position an organic molecule on a piece of indium arsenide, then placed charged metal atoms around it. Stefan Fölsch, one of the researchers on the project, explains how it works:

“[T]he molecule is only weakly bound to the [surface]. So, when we apply a bias voltage... single electrons can tunnel between template and tip by hopping via nearly unperturbed molecular orbitals... the charged atoms nearby provide the electrostatic gate potential that regulates the electron flow and the charge state of the molecule.”

In other, simpler words, it works quite a lot like a normal transistor: apply some input voltage, and the internal workings of the transistor provide a different output depending on the input. The research is published in Nature Physics.